US Patent No. 9,249,949

LIGHTING DEVICE AND PROJECTION-TYPE DISPLAY DEVICE USING THE SAME INCLUDING A COLOR-COMBINING PRISM


Patent No. 9,249,949
Issue Date February 02, 2016 
Title Lighting Device And Projection-type Display Device Using The Same Including A Color-combining Prism
Inventorship Masateru Matsubara, Tokyo (JP)
Assignee NEC DISPLAY SOLUTIONS, LTD., Tokyo (JP)

Claim of US Patent No. 9,249,949

1. A lighting device comprising:
an excitation light source unit that supplies excitation light;
a phosphor unit that is excited by excitation light supplied from said excitation light source unit to emit fluorescence;
first and second solid-state light sources, a color of emitted light of each source being different from each other;
a color-combining prism that includes a first rectangular prism, a second rectangular prism, a trapezoid-shaped prism and
a parallelogram-shaped prism; and

first to third reflection units, each unit including a dichroic film whose film surface is disposed to cross a center ray
of a luminous flux of the fluorescence emitted from said phosphor unit, and moreover, to be orthogonal to a plane containing
the center ray;

wherein:
said excitation light source unit and said first and second solid-state light sources are arranged on one side of the center
ray of the luminous flux of the fluorescence when viewed from a direction perpendicular to the plane;

said first reflection unit comprises a surface in which said first rectangular prism and said trapezoid-shaped prism are bonded
together;

said second reflection unit comprises a surface in which said trapezoid-shaped prism and said parallelogram-shaped prism are
bonded together;

said third reflection unit comprises a surface in which said parallelogram-shaped prism and said second rectangular prism
are bonded together,

said dichroic film of said first reflection unit is provided at a position at which a luminous flux of the excitation light
supplied from said excitation light source unit crosses the center ray of the luminous flux of the fluorescence emitted from
said phosphor unit, reflects the excitation light from said excitation light source unit toward said phosphor unit, and transmits
the fluorescence from said phosphor unit;

said dichroic film of said second reflection unit is provided at a position at which a luminous flux of a first light supplied
from said first solid-state light source crosses the luminous flux of the fluorescence from said first reflection unit, reflects
the first light from said first solid-state light source toward said third reflection unit, and transmits the fluorescence
from said first reflection unit; and

said dichroic film of said third reflection unit is provided at a position at which a luminous flux of a second light supplied
from said second solid-state light source crosses both the luminous flux of the fluorescence and the luminous flux of the
first light that are supplied from said second reflection unit, transmits the fluorescence and the first light from said second
reflection unit, and reflects the second light from said second solid-state light source in a traveling direction of the transmitted
light.